1. Field of the Invention
The invention generally relates to an improved transformer. More particularly, the invention relates to an improved transformer, in which a buffer region is used to hold the division point formed by the secondary wire so that the secondary wire would not be affected or pressed against by the primary wire and hence would not be prone to breakage. Therefore, quality and reliability of the transformer may be improved.
2. Description of the Prior Art
The coil type transformer has been around for more than 100 years. Many improvements and modifications have been made to improve the coil type transformer. Despite these improvements and modifications, the coil type transformer operates according to the same physical principle, mutual induction.
In the coil type transformer, mutual induction occurs if an emf is induced in a coil because of current changes in a second coil. A primary coil and the secondary coil are wound around the same iron core. The primary coil is connected to the source of electrical energy and the secondary coil is connected to a load. When ac is applied to the primary coil, changes in magnetic flux would occur in the iron core and the changes would cause an ac with the same frequency in the secondary coil. The ratio of primary voltage (or emf) to secondary voltage (or emf) is in proportional to the ratio of the number of turns on the primary coil to the number of turns on the secondary coil. Therefore, if the number of turns on the secondary coil is more than the number of turns on the primary coil, the output voltage is greater than the input voltage and it is called a step-up transformer; conversely, if the number of turns on the secondary coil is less than the number of turns on the primary coil, the output voltage is less than the input voltage and it is called a step-down transformer.
Therefore, coils are the most important parts of the coil type transformer. In addition to the quality of the wires, how winding is done is quiet important. Especially, in small-size step-down transformer, a very fine wire is usually used for the winding; therefore, the wire is prone to breakages (which may lead to a short circuit) and damages if the winding is not done meticulously.
Please refer to FIG. 5, which is a side view illustrating the secondary winding in the transformer of the prior art. The transformer has a main body, a primary winding partition 31 and several secondary winding partitions 32. A secondary wire 42 is wound around the core on the secondary winding partitions 32. One end of the secondary wire passes the primary winding partition 31 and is connected to one of several primary leads 312. Also, the primary wire 41 is wound around the iron core on the primary winding partition 31.
The coil type transformer of the prior art has the following disadvantages:
1. The secondary wire 42 is usually a thinner wire and has to pass the primary winding partition 31. Then the primary wire 41 is wound around the core on the primary winding partition 31. Therefore, the secondary wire 42 is pressed and squeezed by the primary wire 41 and hence is prone to breakage and damage.
2. Before the secondary wire 42 goes into the buffer region, the secondary wire 42 is folded for several times and then is twisted and rolled for several turns to make the wire thicker. Therefore, a division point 421 is formed and is prone to breakage because it is pressed against and squeezed by the primary wire 41.
As a result, the primary winding 41 has to be done meticulously to avoid the breakage of the secondary wire 42. Thus, efficiency in assembly is impeded. In addition, because the division point 421 is buried under the primary wire 41, troubleshooting can not be carried out easily.
In addition, the thicker secondary wire 42 may be easily in twine with or tangled up with the other segment of the secondary wire 42 in the secondary winding partitions 32. This may cause a short circuit of the secondary wire 42. Such short circuit may cause the transformer to burn.
From the above, we can see that the transformer of the prior art has many disadvantages and drawbacks and needs to be improved. To eliminate the disadvantages of the transformer of the prior art, the inventor has put a lot of effort into the subject and has successfully come up with the improved transformer of the present invention.